The video encoding device, after digitalizing moving image signals being inputted from the outside, performs an encoding process in accordance with a predetermined image encoding technique, thereby to generate syntax data, i.e. bit streams.
There exists ITU-T Recommendation H.264/AVC (Advanced Video Coding) as one of image encoding techniques (see Non-patent document 1). The H.264/AVC is equivalent to ISO/IEC 14496-10 AVC. The H.264/AVC is for subjecting a syntax element (SE), being coding data of a macroblock (MB) layer or a lower ranking layer to entropy encoding by selecting CAVLC (Context-based Adaptive Variable Length Coding), being a Huffman coding scheme, or CABAC (Context-based Adaptive binary Arithmetic Coding), being an arithmetic coding scheme. Additionally, the SE of the MB layer is described in 7.3.5 Macroblock layer syntax of the Non-patent document 1. Further, hereinafter, the matter stipulated in the H.264/AVC is called an H.264 specification.
It is said that selecting CABAC for the entropy encoding yields a coding quantity reduction effect of 15% or so on the average as compared with the case of selecting the CAVLC. Further, the encoder of a Joint Model technique is known as a reference model of an H.264/AVC encoder (hereinafter, referred to as a general-purpose video encoding device).
A configuration and an operation of the general-purpose video encoding device that outputs a bit stream with a digitalized image frame taken as an input will be explained by making a reference to FIG. 9. The video encoding device shown in FIG. 9 includes an original image frame buffer 10, an MB encoding device 20, a rate controlling device 30, and a decoded image frame buffer 40. With regard to a QCIF (Quarter Common Intermediate Format) image frame, the original image frame buffer 10 stores image data shown in FIG. 10. The image frame is divided into luminance pixels of a 16.times.16 pixel block that are called an MB, and pixel blocks having color difference pixels (Cr and Cb) of an 8.times.8 pixel block as a component.
The MB encoding device 20, as a rule, encodes the MB in an order of a luster scan reaching from upper left to lower right of the image frame.
The rate controlling device 30 monitors the output bit number of the bit streams that the MB encoding device 20 outputs, regulates a quantized parameter being supplied to the MB encoding device 20, and takes a rate controls so that the number of the bit streams approaches a target bit number. Specifically, when the bit number of the bit streams becomes larger than a target bit number, the rate controlling device 30 supplies the quantized parameter of which a quantization width is larger to the MB encoding device 20, and contrarily, when the bit number of the bit streams becomes smaller than a target bit number, the rate controlling device 30 supplies the quantized parameter of which a quantization width is smaller to the MB encoding device 20.
The decoded image frame buffer 40 loads and stores a decoded image by the MB encoding device 20 at a timing that the MB encoding device 20 has completed the encoding of one MB in order to utilize it for succeeding encoding (prediction).
Next, an internal configuration and an operation of the MB encoding device 20 will be explained. As shown in FIG. 9, the MB encoding device 20 includes a read device 210, a predicting device 220, a video encoding (Venc) device 230, and an entropy encoding (EC) device 240. The read device 210 includes an original image MB memory 211 and a reference image memory 212. The video encoding device 230 includes a converter/quantizer 231, an inverse quantizer/inverse converter 232, and a decoded image MB memory 233. The entropy encoding device 240 includes an entropy encoder 241, an output buffer 242, a controlling device 243, and a context duplication memory 244.
The to-be-encoded images of the MB (hereinafter, referred to as an original image org), out of the image frames stored in the original image frame buffer 10, are stored in the original image MB memory 211. The images necessary for predicting and encoding the to-be-encoded MB (hereinafter, referred to as a reference image ref), out of the image frames stored in the decoded image frame buffer 40, are stored in the reference image memory 212.
The predicting device 220 detects a prediction parameter param, which enables the original image to be preferredly encoded, from the reference images stored in the decoded image frame buffer 40 and the decoded image MB memory 233, and generates a prediction image pred and a prediction error image pe. The prediction parameter is supplied to the entropy encoder 241. The prediction error image pe is supplied to the converter/quantizer 231. The prediction error image pe, which is added to an output of the inverse quantizer/inverse converter 232, is stored as a decoded image in the decoded image MB memory 233. However, when a necessity for original image PCM (Pulse Code Modulation) re-encoding to be later described has arisen, the original image being supplied from the original image MB memory 211 is stored as a decoded image in the decoded image MB memory 233.
There exist two kinds of predictions, i.e. an intra-frame prediction and an inter-frame prediction. The prediction image and the prediction error image in the intra-frame prediction/inter-frame prediction will be explained. When the intra-frame prediction is carried out, the predicting device 220 makes a reference to a past decoded image of which a display time is identical to that of the current to-be-encoded image frame, utilizes a correlation of the pixels within the image frame (a spatial direction), and generates the prediction image pred. Various patterns of the intra-frame prediction in a 4.times.4 pixel block size in which the MB has been yet finely divided are shown as one example in an explanatory view of FIG. 11 (for the intra-frame prediction in the case of the color difference and others, see 8.3 section Intra prediction process of the Non-patent document 1).
Each intra_dir in FIG. 11(A) to (I) is an intra-screen predictive-direction parameter indicative of a direction etc. of the intra-frame prediction. The predicting device 220, when selecting the intra-frame prediction, generates the prediction image pred according to the intra-screen predictive-direction parameter intra_dir. For convenience of the succeeding explanation, the intra-frame prediction is defined as Equation 1.pred=intra_prediction(ref,intra_dir)  [Numerical equation 1]
In Equation 1, intra_prediction ( ) is a function for generating an intra-frame prediction image from the reference image ref according to the intra-screen predictive-direction parameter intra_dir.
When the inter-frame prediction is carried out, the predicting device 220 makes a reference to the past decoded image of which the display time differs from that of the current to-be-encoded image frame, utilizes a correlation within the image frames (a temporal direction), and generates the prediction image pred. The inter-frame prediction of a 16.times.16 pixel block size will be explained as one example of the inter-frame prediction by making a reference to an explanatory view of FIG. 12 (for the inter-frame prediction of the other pixel block sizes, see 8.4 section Intra prediction process of the Non-patent document 1).
Each of movement vectors mv_x and mv_y shown in FIG. 12 is a prediction parameter of the inter-frame prediction. The predicting device 220, when selecting the inter-frame prediction, generates the prediction image pred according to the movement vectors mv_x and mv_y. For convenience of the succeeding explanation, the inter-frame prediction is defined as Equation 2.pred=inter_prediction(ref,mv—x,mv—y)  [Numerical equation 2]
In Equation 2, inter_prediction ( ) is a function for generating an inter-frame prediction image from the reference image ref according to the movement vectors mv_x and mv_y. Additionally, the H.264 specification stipulates that a pixel precision of the movement vector is one quarter pixel.
The predicting device 220 utilizes cost functions (predictive evaluation values) of Equation 3, and Equation 4 to Equation 7, and detects the prediction parameter param for generating the foregoing prediction image pred. The so-called prediction parameter is the intra-screen predictive-direction intra_dir with the intra-frame prediction, and is the movement vectors mv_x and mv_y, etc. with the inter-frame prediction (for other prediction parameters, see 7 section Syntax and semantics of the Non-patent document 1). A difference between the prediction image pred corresponding to the detected prediction parameter param, and the original image org is called a prediction error image pe (see Equation 6).
                              Cost          ⁡                      (            param            )                          =                                            ∑                              idx                =                0                            15                        ⁢                                                  ⁢                          S              ⁢                                                          ⁢              A              ⁢                                                          ⁢              T              ⁢                                                          ⁢              D              ⁢                                                          ⁢                              (                idx                )                                              +                                    λ              ⁡                              (                QP                )                                      ×                          R              ⁡                              (                param                )                                                                        [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          3                ]                                                      S            ⁢                                                  ⁢            A            ⁢                                                  ⁢            T            ⁢                                                  ⁢            D            ⁢                                                  ⁢                          (              idx              )                                +                      0.5            ×                                          ∑                                  x                  =                  0                                3                            ⁢                                                          ⁢                              ∑                                  y                  =                  0                                3                                                    ❘                              H            ⁡                          (              idx              )                                xy                                    [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          4                ]                                          H          ⁢                      (            idx            )                          =                              [                                                            1                                                  1                                                  1                                                  1                                                                              1                                                  1                                                                      -                    1                                                                                        -                    1                                                                                                1                                                                      -                    1                                                                                        -                    1                                                                    1                                                                              1                                                                      -                    1                                                                    1                                                                      -                    1                                                                        ]                    ⁢                                                                 [                                                                  ⁢                                                                                                    p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          0                              ,                              0                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          0                              ,                              1                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          0                              ,                              2                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          0                              ,                              3                                                        )                                                                                                                                                                                                  p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          1                              ,                              0                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          1                              ,                              1                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          1                              ,                              2                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          1                              ,                              3                                                        )                                                                                                                                                                                                  p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          2                              ,                              0                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          2                              ,                              1                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          2                              ,                              2                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          2                              ,                              3                                                        )                                                                                                                                                                                                  p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          3                              ,                              0                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          3                              ,                              1                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          3                              ,                              2                                                        )                                                                                                                                                              p                        ⁢                                                                                                  ⁢                                                                              e                            idx                                                    ⁡                                                      (                                                          3                              ,                              3                                                        )                                                                                                                                              ⁢                                                                  ]                            ⁢                                                                 [                                                                                    1                                                                    1                                                                    1                                                                    1                                                                                                            1                                                                    1                                                                                              -                          1                                                                                                                      -                          1                                                                                                                                    1                                                                                              -                          1                                                                                                                      -                          1                                                                                            1                                                                                                            1                                                                                              -                          1                                                                                            1                                                                                              -                          1                                                                                                      ]                                ⁢                                                                  ⁢                                                                  ⁢                                                                                                                          [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          5                ]                                          p          ⁢                                          ⁢                                    e              idx                        ⁡                          (                              y                ,                x                            )                                      =                              org            ⁡                          (                                                                    b                    ⁢                                                                                  ⁢                    4                    ⁢                                                                                  ⁢                                          y                      idx                                                        +                  y                                ,                                                      b                    ⁢                                                                                  ⁢                    4                    ⁢                                                                                  ⁢                                          x                      idx                                                        +                  x                                            )                                -                      pred            ⁡                          (                                                                    b                    ⁢                                                                                  ⁢                    4                    ⁢                                                                                  ⁢                                          y                      idx                                                        +                  y                                ,                                                      b                    ⁢                                                                                  ⁢                    4                    ⁢                                                                                  ⁢                                          x                      idx                                                        +                  x                                            )                                                          [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          6                ]                                          λ          ⁡                      (            QP            )                          =                  2                                    (                              QP                -                12                            )                        ⁢                          /                        ⁢            6                                              [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          7                ]                                          (                                    b              ⁢                                                          ⁢              4              ⁢                                                          ⁢                              x                idx                                      ,                          b              ⁢                                                          ⁢              4              ⁢                                                          ⁢                              y                idx                                              )                ⁢                  {                                    0              ≤                              b                ⁢                                                                  ⁢                4                ⁢                                                                  ⁢                                  x                  idx                                            ≤              12                        ,                          0              ≤                              b                ⁢                                                                  ⁢                4                ⁢                                                                  ⁢                                  y                  idx                                            ≤              12                                }                                    [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          8                ]            
Additionally, Equation 3 is an equation for explaining the calculation of the predictive evaluation value in the H.264. Equation 4 is an equation for explaining the calculation of SATD(idx) in Equation 3. Equation 5 is an equation for explaining the calculation of H(idx) in Equation 4. Equation 6 is an equation for explaining the calculation of peidx(y,x) in Equation 5. Equation 7 is an equation for explaining the calculation of λ(QP) in Equation 3. Equation 8 is an equation for explaining b4x and b4y in Equation 6. Further, QP in Equation 3 to Equation 7 is a quantized parameter of the MB, idx is a number of a 4.times.4 block inside the MB shown in FIG. 10, and b4x and b4y are indicative of coordinates inside the MB of an upper left corner of the 4.times.4 block that corresponds to idx.
Next, the converter/quantizer 231 subjects the prediction error pe being supplied from the predicting device 220 to a frequency transformation in a unit of the block finer than the MB (hereinafter, referred to as a conversion block), and converts (transforms) a region thereof from a space region into a frequency region. The prediction error image of which the region has been converted into a frequency region is called a conversion coefficient T.
In addition hereto, the converter/quantizer 231 quantizes the conversion coefficient T with a quantization width that corresponds to the quantized parameter QP being supplied from the rate controlling device 30. The quantized conversion coefficient, as a rule, is called a transformed-quantized value L. The transformed-quantized value L is supplied to the inverse quantizer/inverse converter 232 for a purpose of the succeeding encoding, and is supplied to the entropy encoding device 240 in order to form a bit stream.
A succeeding operation will be explained by paying an attention to the transformed-quantized value L being supplied to the inverse quantizer/inverse converter 232.
The inverse quantizer/inverse converter 232 subjects the transformed-quantized value L being supplied from the converter/quantizer 231 to an inverse quantization, and further to an inverse frequency transformation, thereby to return the region thereof to the original space region. The prediction error image of which region has been return to the original space region is called a restructure prediction error image pe_rec.
The restructure prediction error image pe_rec being supplied from the inverse quantizer/inverse converter 232, to which the prediction image pred being supplied from the predicting device 220 has been added as shown in Equation 9 for explaining the reference image in the H.264 specification, is stored as a decoded image rec in the decoded image MB memory 233. The decoded image rec stored in the decoded image MB memory 233, subsequent to it, is loaded into the predicting device 220 or the decoded image frame buffer 40, and becomes a reference image.rec=pred+pe_rec  [Numerical equation 9]
Next, a succeeding operation will be explained by paying an attention to the transformed-quantized value L being supplied to the entropy encoding device 240.
The entropy encoding device 240 includes an entropy encoder 241, an output buffer 242, a controlling device 243, and a context duplication memory 244. The entropy encoder 241 subjects input data to entropy encoding, and supplies output bits to the output buffer 242. The controlling device 243 monitors the number of the output bis of the entropy encoder 241, and controls an operation of the other devices. The context duplication memory 244 is a memory for storing duplication of context data that is later described.
The controlling device 243 monitors the number of the output bits of the entropy encoder 241, and controls the entropy encoder 241 and the output buffer 242 by use of control signals (an entropy encoding control signal and an output buffer signal).
When, even though the controlling device 243 subjects input data of all of one BM to the entropy encoding, its output bit number does not exceed an upper-limit bit number being stipulated in the H.264 specification (Upon making a reference to Annex AA.3 Levels of the Non-patent document 1, it is 3,200 bits), the controlling device 243 outputs the bits stored in the output buffer 242 as syntax data of the MB by use of the output buffer control signal. Additionally, the upper-limit bit number per one MB that is stipulated in the H.264 specification is, hereinafter, referred to as a stipulation value.
At the moment that the number of the output bits obtained by subjecting the input data of one MB to the entropy encoding exceeds the stipulation value of the MB bit number, the controlling device 243 stops an operation of the entropy encoder 241 by use of the entropy encoding control signal for the time being, and cancels all bits of the output buffer 242 by use of the output buffer control signal. That is, contents of the output buffer 242 at this time point are not regarded as syntax data. The controlling device 243, after cancelling the bits, starts the entropy encoder 241 by use of the entropy encoding control signal, and causes entropy encoder 241 to re-encode the input image data so that the bit number becomes equal to or less than the stipulation vale.
Next, an internal configuration and an operation of the entropy encoder 241 in the case of having selected the CABAC as entropy encoding will be explained. As shown in FIG. 13, the entropy encoder 241 is configured of an entropy encoding unit 2416 including a binarizing device 2411, a binary arithmetic encoding device 2412, and a context modeling device 2413, a switch 2414, and a switch 2415.
A PCM re-encoding operation in the entropy encoding device will be explained.
The entropy encoder 241, at first, stops a process of subjecting the input data to the entropy encoding for the time being. Next, it loads the context data preserved in the context duplication memory 244 into the context modeling device 2413. Thereafter, the binarizing device 2411 generates a bin (binary symbol) of the prediction parameter indicative of a commencement of the PCM, and supplies it to the binary arithmetic encoding device 2412. Simultaneously therewith, the context modeling device 2413 supplies the context data corresponding to the bin to the binary arithmetic encoding device 2412. The binary arithmetic encoding device 2412 subjects the bin to the arithmetic encoding by employing the context data, and returns the context data updated by the arithmetic encoding to the context modeling device 2413 while writing out the output bit to the output buffer 242 via the switch 2415. After the binary arithmetic encoding device 2412 finishes subjecting the bin of the prediction parameter indicative of a commencement of the PCM to the arithmetic encoding, it make a switchover of the switch 2414, loads the image stored in the original image MB memory 211, re-encodes it without changing a status of the PCM image, and writes out it to the output buffer 242.
The process of re-encoding the original image for which the above-mentioned conversion process, being a process of re-encoding, has not been applied with the PCM is called an original image PCM re-encoding process (see Patent document 1). It is said that utilizing the original image PCM re-encoding process makes it possible to guarantee not only the entropy encoding device of the encoding device but also the entropy decoding device in the decoding side for keeping the processing time thereof at a level of a certain constant time because the image that is completely unconvertible and unpredictable can be encoded without distortion and yet with a constant bit number equal to less than the stipulation value of the MB bit number.
Further, there exists the method of predicting the MB output bit number of the MB prior to the CABAC and making a switchover to the PCM encoding employing the encoded image as a method of observing the stipulation value of the MB bit number without being accompanied by the re-encoding (see Patent document 2).
Next, the encoding process of the CABAC will be explained in details.
As shown in FIG. 19, for example, the general-purpose entropy encoder for realizing the CABAC is configured of a binarizer 101, a switch 111, a binary arithmetic encoder 102, and a context modeler 103. Additionally, a configuration shown in FIG. 14 is equivalent to the configuration of the entropy encoder 2416 shown in FIG. 13. The context modeler 103 is initialized before performing the MB process for a slice head by employing a first QP of the MB (see 9.3.1 Initialization process of the Non-patent document 1).
The binarizer 101 converts the SE being inputted into a binary sequence according to a rule stipulated with the specification (for a correspondence between the SE and the binary sequence conversion, see 9.3.2 Binarization process of the Non-patent document 1). Next, the binary arithmetic encoder 102 subjects each symbol (bin) of the binary sequence being supplied from the binarizer 101 to the binary arithmetic encoding by utilizing the context (more probable symbol (MPS)) being supplied from context modeler 103 and a state index (state_idx).
Additionally, the MPS of the context corresponds to valMPS in the non-patent document 1, and state_idx to pStateIdx in the non-patent document 1. As a rule, in the binary arithmetic encoding, a numerical line [0.1] is divided responding to an occurrence probability ρ of the symbol, and the binary decimal value of a representative point of a final partial block is outputted with the bits as a final coding language. An operational example of the usual binary arithmetic encoding for a three-symbol input (110) is shown in FIG. 15.
In the binary arithmetic encoding of the H.264 specification, an occurrence probability (rLPS(i)) of a less-probable-symbol (LPS) at the time of processing the current bin corresponds to ρ in FIG. 15. rLPS(i) can be expressed with the following Equation 10.rLPS(i)=range Tab LRS[state—idx][qCodIrangeIdx]/Rrange(i)  [Numerical equation 10]
Herein, it is assumed that Erange(i) (which corresponds to codIRange in the Non-patent document 1) is an arithmetic range at the time of processing the current bin, qCodIRangeIdx(i) is an arithmetic range index being obtained from higher bits of Erange(i), and rangeTabLPS[64] [4] (which corresponds to table 9-35 in the Non-patent document 1) is a less-probable-symbol range table (see 9.3.4 Arithmetic encoding process (informative) of the Non-patent document 1).
The binary arithmetic encoder 102 performs a process equivalent to the execution of Equation 11 and Equation 12 described below by employing rLPS(i) (see 9.3.4.2 Encoding process for a binary decision (informative) of the Non-patent document 1), thereby completing the process of the binary arithmetic encoding for one bin. Herein, it is assumed that Elow(i) (which corresponds to codILow in the non-patent document 1) is an arithmetic lower-limit at the time of processing the current bin. There exits Bypass encoding as well in which rLPS(i) always becomes a fixed value (see 9.3.4.4 Bypass Encoding process for a binary decisions (informative) of the Non-patent document 1).
                              Erange          ⁡                      (                          i              +              1                        )                          =                  {                                                                                                                Erange                      ⁡                                              (                        i                        )                                                              -                                          rLPS                      ⁡                                              (                        i                        )                                                                              ⁢                                                                                                                    Λ                                                              if                  ⁢                                                                          ⁢                                      (                                          bin                      =                                              M                        ⁢                                                                                                  ⁢                        P                        ⁢                                                                                                  ⁢                        S                                                              )                                                                                                                        rLPS                  ⁡                                      (                    i                    )                                                                              Λ                                                              otherwise                  .                                                                                        [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          11                ]                                          Elow          ⁡                      (                          i              +              1                        )                          =                  {                                                                      Elow                  ⁡                                      (                    i                    )                                                                              Λ                                                              if                  ⁢                                                                          ⁢                                      (                                          bin                      =                                              M                        ⁢                                                                                                  ⁢                        P                        ⁢                                                                                                  ⁢                        S                                                              )                                                                                                                                            Erange                    ⁡                                          (                      i                      )                                                        -                                      rLPS                    ⁡                                          (                      i                      )                                                                                                  Λ                                                              otherwise                  .                                                                                        [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          12                ]            
Further, in the binary arithmetic encoding of the H.264 specification, so as to carry out the arithmetic encoding that meets an occurrence frequency of the input symbol, whenever the binary arithmetic encoding of one bin is completed, the MPS of the context utilized for the binary arithmetic encoding of the bin is updated with following Equation 13, and simultaneously therewith, a value of state_idx of the context is updated according to a state transit table (Table 9-36 of the Non-patent document 1).
                              M          ⁢                                          ⁢          P          ⁢                                          ⁢          S                =                  {                                                                      1                  -                                      M                    ⁢                                                                                  ⁢                    P                    ⁢                                                                                  ⁢                    S                                                                              Λ                                                              (                                                            state_                      ⁢                      idx                                        =                                                                  0                        ⁢                                                                                                  ⁢                                                  AND                          ⁢                          bin                                                                    ≠                                              M                        ⁢                                                                                                  ⁢                        P                        ⁢                                                                                                  ⁢                        S                                                                              )                                                                                                      M                  ⁢                                                                          ⁢                  P                  ⁢                                                                          ⁢                  S                                                            Λ                                                              Otherwise                  .                                                                                        [                  Numerical          ⁢                                          ⁢          equation          ⁢                                          ⁢          13                ]            
As described above, the binary arithmetic encoding of the H.264 specification, which is for managing a probability of the less-probable-symbol with the less-probable-symbol table and the state transit table, is called table-driven binary arithmetic coding.
Successively subjecting all bins being inputted to the foregoing binary arithmetic encoding allows the arithmetic encoding output bit (bit stream) to be obtained.    Patent document 1: JP-P2006-93777A    Patent document 2: Japanese Patent Application No. 2005-300933    Non-patent document 1: ITC-T Recommendation H.264 Advanced video coding for generic audiovisual services, may, 2005 (Prepublished Version)